1. Field of the Invention
The present invention relates to a pressure connecting terminal to be connected to a wire terminal.
2. Description of the Related Art
FIG. 1 is a perspective view showing an example of a conventional pressure connecting terminal. This pressure connecting terminal 1 is formed by punching and bending a plated conductive metal plate, and basically has a substantially U-shaped section consisting of bottom wall 1a and both side walls 1b, 1b. It has a cylindrical and electric contact portion 2 provided on a front portion in the length direction and a pressure connecting portion 3 provided on a rear portion thereof, to which a coated wire is to be connected by pressure.
The pressure connecting portion 3 has a pair of pressure connecting blades 4, 4 erected from a bottom wall 1a and provided in the back and forth direction. There are slits 5, 5 in the pressure connecting blades 4, 4 such that they are cut downward from the center at a top end of each thereof.
In the pressure connecting portion 3, a wire insertion portion 6 is formed in the length direction by punching out and remaining right and left portions act as bridge portions 7, 7 for joining top ends of the pressure connecting blades 4, 4. Shoulder portions 8, 8 protruded outward are formed on these bridge portions 7, 7 and the shoulder portions 8, 8 are fit to fitting grooves 9, 9 formed by cutting top edge portions of both side walls 1b, 1b. 
For the pressure connecting portion 3, a U-shaped cut-in is formed in the bottom wall 1a such that two long sides extending in the length direction toward an electric contact portion 2 and a front side are continuous with each other and then, that the cut portion is drawn to a rear side remaining on the bottom wall 1a of the pressure connecting portion 3 so that it is bent three-dimensionally in the substantially reverse U shape (see Japanese Utility Model Application Laid-Open No. 7-22468).
When connecting a coated wire to the pressure connecting portion 3 of the above described pressure connecting terminal 1, the coated wire is pushed into between the pair of the pressure connecting blades 4, 4 in the wire insertion portion 6 from above.
Because the pressure connecting blades 4, 4 provide broken faces formed by cutting the bottom wall 1a, it is necessary to carry out plating during or after assembly of the pressure connecting terminal 1 in order to secure electric connecting reliability. For the reason, production process of the pressure connecting terminal 1 becomes complicated thereby leading to an increase of production cost.
Further, because the coated wire is connected to the pressure connecting portion only through the pressure connecting blades 4, 4, there is such a fear that pressure connecting force weakens to increase resistance thereby causing unconductivity when an external force such as a pulling force is applied to the coated wire. That is, there is a problem that its mechanical connecting reliability is low.
An object of the present invention is to provide a pressure connecting terminal capable of improving both electrical connecting reliability and mechanical connecting reliability and which can be produced at low cost.
To achieve the above object, according to the present invention, there is provided a pressure connecting terminal comprising: an electric contact portion provided on a side thereof for contacting a mating terminal; a pair of side wall portions formed on the other side by bending both sides of a bottom wall while an end of a coated wire being connected and conductive therewith; a coated wire crimping portion comprising a pair of grip pieces extended from the pair of the side wall portions so that the coated wire is to be crimped; a first pressure connecting portion provided between the coated wire crimping portion and the electric contact portion, which is located on the side of the electric contact portion and comprises a pair of punched blades each having a plated face formed by protruding the pair of the side wall portions inward, so that the coated wire is to be pressed in between the punched blades to secure conductive connection; and a second pressure connecting portion comprising an erected piece raised between the first pressure connecting portion and the pair of the grip pieces such that the erected piece is erected by being supported by the pair of the side wall portions on the bottom wall, so that the coated wire pressed in a slit formed from a top end thereof toward the bottom wall is prevented from moving in an axial direction so as to secure conductive connection.
In this pressure connecting terminal, an end of the coated wire is connected to the first pressure connecting portion and the second pressure connecting portion by pressure and by crimping the coated wire by the grip pieces. Further, the core of the wire is brought into contact with a pair of the punched blades each having a plated face in the first pressure connecting portion so as to secure a conductivity. Further, moving of the coated wire in the axial direction is restricted by the erected piece to which the coated wire is connected by pressure in the second pressure connecting portion. Thus, even if an external force is applied in the direction for the end of the coated wire to leave the pressure connecting terminal, most of this external force is supported by the second pressure connecting portion so that the external force can be prevented from being applied to the first pressure connecting portion. Therefore, both electric connecting reliability and mechanical reliability are improved.
According to the invention, there is provided a pressure connecting terminal according to the first aspect wherein the erected piece is formed by cutting the bottom wall in the U shape and raising it in the direction of an opening and has a pair of shoulder portions engaging with fitting grooves formed in the pair of the side wall portions, on both sides of the erected piece.
In this pressure connecting terminal, because the erected piece is formed by cutting part of the bottom wall, the erected piece can be fixed more firmly between the pair of the side wall portions and when the coated wire is connected to the second pressure connecting portion by pressure, moving of the coated wire in the axial direction can be restricted more securely. As a result, an external force applied to the first pressure connecting portion can be further reduced. Further, because part of the bottom wall is only bent and supported by the pair of the side wall portions, production of this pressure connecting terminal is very easy.
According to the present invention, there is provided a pressure connecting terminal according to the first aspect wherein the erected piece comprises a pair of bent pieces formed by cutting the pair of the side wall portions in the U shape and bending them inward, so that the slit is formed between the bent pieces.
In this pressure connecting terminal, because the erected piece is formed of the pair of the bent pieces formed by cutting partly each of the pair of the side wall portions, the erected piece can be formed more firmly over the bottom wall, so that the moving of the coated wire in the axial direction can be restricted more securely. Further, because the erected piece can be formed by cutting partly the pair of the side wall portions, production of the pressure connecting terminal is facilitated.